Thanks to the many who helped I now have the 8100 up and running ( replaced caps, zeners, Qi13, 14) and it sounds really good (much better than it did). Next I will start on the Power Amp Unit (I replaced the main filter caps while doing the control amp). I plan on changing the trimmers and: "Main board (power amp board): De1,2 (EQA01-24R) to 1n5252B 24V zeners De3,4 (EQA01-30R) to 1n5256B 30V zeners De16,17 (W06B) to 1n4007 Protection circuit Qe31 (relay driver - 2sc1735) to KSC2690AYS Qe29 (2sc1222) to KSC1845 Qe30 (2sc1681) to KSC1845" Thanks for this list goes to Gort69 .. I have; however, run into a small(?) problem in that while turning the Center Voltage Trim pots .. nothing happens? I am doing the adjustment according to page 14 of the service manual?? Also the Bias on the left channel is 14mv (per spec) while the best I can get on the right channel is 29mv and this is after one hour of running??